Occurrence and Properties of Copper-Tolerant Strains ofPseudomonas syringaeIsolated from Fruit Trees in California

Approximately 40% of the ice-nucleation-active strains of Pseudomonas syringae isolated from asymptomatic leaves and flowers from almond and navel orange trees from orchards with a history of copper usage were able to grow in a culture medium amended with 0.32 mM CuSO 4 . While more than one-half of the strains were highly sensitive to cupric ions, some strains could tolerate as much as 1.12 mM CuSO 4 in a culture medium (...)